Proliferating cell nuclear antigen of Ulva prolifera is involved in the response to temperature stress

Ulva prolifera is the most common specie causative to green tide,and its growth is sensitive to temperature stress.However,the mechanisms of U.prolifera response to temperature stress remain elusive.In this study,high temperature(36℃)stimulus promoted the death of unformed cell wall protoplasts and delayed the division of formed cell wall protoplasts,while low-temperature(4℃)stimulus did not,suggesting that the mechanisms of the response of U.prolifera to high and low temperature stresses are different.Transcriptome results show that proliferation-related genes were differentially expressed under high and low-temperature stresses,especially the proliferating cell nuclear antigen(PCNA)and cyclins(CYCs).Subsequently,the interaction between PCNA and Cyclin A was confirmed by Co-immunoprecipitation,yeast two-hybrid,and so on.Furthermore,high-and low temperature stresses induced the expression of PCNA and Cyclin A in varying of degrees,and activated extracellular signal-regulated kinase(ERK)signal pathway.These results suggest,PCNA,Cyclin A,and ERK signal pathway played important roles in the resistance of U.prolifera to temperature stress.Interestingly,high-temperature stress induced an increase of miR-2916 in abundance,and exhibiting reverse expression of PCNA;and PCNA was target gene of miR-2916,suggesting that miR-2916 protected U.prolifera from high-temperature stress via post-transcriptionally regulation of PCNA.This study laid a foundation for understanding the function of PCNA and Cyclin A,moreover,it has a guiding significance to explore the mechanisms of the response to temperature stress from proliferation-related genes regulatory networks in U.prolifera.

The Relationship of Expression of bcl-2, p53, and Proliferating Cell Nuclear Antigen (PCNA) to Cell Proliferation and Apoptosis in Renal Cell Carcinoma

To investigate the relationship of bcl-2, p53, proliferating cell nuclear antigen (PCNA) to cell proliferation, apoptosis and pathological parameters, the patterns of cell growth and turnover in renal cell carcinoma (RCC), formalin-fixed and paraffin-embedded tissue blocks from 34 patients with RCC were examined. Cell proliferation activity was detected by PCNA immunostaining and the proliferation index (PI) was expressed as a percentage of the PCNA-positive cells in the tumor cells. Apoptosis was detected by terminal deoxy- nucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL), and the apoptotic index (AI) was expressed as a percentage of the TUNEL-positive cells in the tumor cells. Expressions of bcl-2 and p53 were assessed immunohistochemically. Our results showed that the PI ranged from 6.0 % to 24.0 % (median 12.3 %) and the AI from 2.0 % to 8.0 % (median 5.4 %) in RCC. The expression of the bcl-2 protein was demonstrated in 15 cases (44.1 %); the expression of the p53 protein, however, was seen in only 3 case. bcl-2 positivity was not associated with PI or AI or any pathological parameters. There were close associations between PI and tumor grade and stage, and a significant relationship between AI and the tumor grade of RCC. Our study suggests that bcl-2 positivity was not associated with PI or AI or any pathological parameters. There are close associations between PI and AI and tumor grade and stage of RCC. Active cell proliferation may be accompanied by frequent apoptosis in RCC.

Influence of norcantharidin on proliferation,proliferation-related gene proteins prolifera-ting cell nuclear antigen and Ki-67 of human gallbladder carcinoma GBC-SD cells

BACKGROUND: Gallbladder carcinoma is a highly lethal and aggressive disease with early metastasis, strong invasion and poor prognosis. Most patients with this disease are at the advanced and un-resectable stage and should be consi- dered for palliative treatment such as chemotherapy and ra- diotherapy. Unfortunately, reports of chemotherapy and radiotherapy for gallbladder carcinoma are disappointing. We investigated the influence of norcantharidin (NCTD) on proliferation, proliferation-related gene proteins PCNA and Ki-67 of human gallbladder carcinoma GBC-SD cells in vitro. METHODS: GBC-SD cell lines of human gallbladder carci- noma were cultured by the cell culture technique. The ex- periment was divided into NCTD group and control group. The tetrazolium-based colorimetric assay was used to evaluate cell growth. The streptavidin-biotin complex method was used to determine the expressions of prolifera- tion-related gene proteins PCNA and Ki-67 of human gall- bladder carcinoma GBC-SD cells. RESULTS: NCTD inhibited the growth and proliferation of GBC-SD cells from 10 mg/L or after 6 hours in a dose- and time-dependent manner, with the IC50 value of 56.18 μg/ ml at 48 hours. After treatment with NCTD, the expression of PCNA (0.932 ±0.031 vs. 0.318 ±0.023, P<0.001) and Ki-67 (0.964 ±0.092 vs. 0.297 ±0.018, P<0.001) proteins were decreased significantly. CONCLUSION: NCTD inhibits the proliferation of human gallbladder carcinoma GBC-SD cells in vitro and the expres- sion of their proliferation-related gene proteins PCNA and Ki-67.

Effect of pre-moxibustion on apoptosis and proliferation of gastric mucosa cells

AIM： TO observe the effects of pre-moxibustion on apoptosis and proliferation of gastric mucosal cell in rats with stress-induced ulcer, and to analyze the relationship between those effects and the expression of heat-shock protein 70 （HSP70）. METHODS： Sixty healthy Sprague Dawley rats were randomly assigned into four groups, namely group A, B, C and D. The animal model of stress ulcer was established by water immersion and restraint stress. The rats in group A, B, and D served as the restraint, model, and non-acupoint controls, respectively, while those in group C received moxibustion at Zusanli and Uangmen points. Immunohistochemical methodology was used to detect the expression of HSP70, apoptosis index （AI, × 10^-6/μm^2） and proliferation index （PCNA-LI, × 10^-6/μm^2）. The mucosal expression of transforming growth factor α （TGF-α） was detected by radioimmunoassay. RESULTS： IVloxibustion at Zusanli and Liangmen points significantly decreased the gastric injury and the apoptosis of gastric mucosal cells, while markedly increased the mucosal expression of TGF-α and HSP70 as well as the proliferation of gastric mucosal cells. Compared with group A, ulcer index （UI） （26.8 ± 9.8 vs 12.0 ± 5.9, P 〈 0.01）, AI （9.6 ± 4.2 vs 4.4 ± 2.6, P 〈 0.05） and expression of HSP70 （9.6 ± 4.2 vs 4.4 ± 2.6, P 〈 0.05） were significantly increased, but the content of TGF-α （104.7 ± 51.2 pg/mL vs 254.0 ± 86.9 pg/mL, P 〈 0.01） and PCNA-LI （6.9 ± 4.7 vs 14.9 ± 4.6, P 〈 0.05） were significantly decreased in group B. However, ulcer index values （UI） and AI were obviously lower in group C compared to groups B and D （14.1 ± 5.4 vs 26.8 ± 9.8 and 26.2 ± 7.7, P 〈 0.01, 3.0 ± 1.6 vs 9.6 ± 4.2 and 8.2 ± 5.2, P 〈0.05, respectively）, but content of TGF-α （237.0 ± 72.6 pg/mL vs 104.7 ± 51.2 pg/mL and 154.1 ± 61.3 pg/mL, P 〈0.01） and expression of HSP70 （0.13 ± 0.03 vs 0.08 ± 0.06 and 0.06 ± 0.04, P 〈 0.05） were higher in group C. Furthermore, the PCNA-LI was significantly higher in group C than in group B （21.6 ± 4.1 vs 6.9 ± 4.7, P 〈 0.01）. CONCLUSION： Moxibustion at Zusanli and Liangmen points has a protective effect on rats gastric mucosa in stress-induced gastric ulcer, which is closely related to its actions in promoting synthesis of TGF-α and proliferation of gastric mucosal cells, suppressing gastric mucosal cell apoptosis, and up-regulating HSP70 expression.

Clinical significance of expression of proliferating cell nuclear antigen and E-cadherin in gastric carcinoma

AIM to investigate the expression of proliferating cell nuclear antigen(p CNA)and E-cadherin in gastric carcinoma and to analyze their clinical significance.METHODS A total of 146 patients were selected for this study,including 38 patients with intestinal metaplasia,42with dysplasia,and 66 with primary gastric cancer.In addition,40 patients with normal gastric tissues were selected as controls.the expression of p CNA and E-cadherin was detected by immunohistochemistry.Differences in p CNA and the E-cadherin labeling indexes among normal gastric mucosa,intestinal metaplasia,dysplasia,and gastric carcinoma were compared.Subjects with normal gastric tissues were assigned to a normal group,while gastric cancer patients were assigned to a gastric cancer group.the difference in p CNA and E-cadherin expression between these two groups was compared.the relationship between expression of p CNA and E-cadherin and clinicopathological features was also explored in gastric cancer patients.furthermore,prognosis-related factors,as well as the expression of p CNA and E-cadherin,were analyzed in patients with gastric cancer to determine the 3-year survival of these patients.RESULTS the difference in p CNA and the E-cadherin labeling indexes among normal gastric mucosa,intestinal metaplasia,dysplasia,and gastric carcinoma was statistically significant(p<0.05).During the transition of normal gastric mucosa to gastric cancer,the p CNA labeling index gradually increased,while the E-cadherin labeling index gradually decreased(p<0.05).the p CNA labeling index was significantly higher and the E-cadherin labeling index was significantly lower in gastric cancer than in dysplasia(p<0.05).the expression of p CNA was significantly higher in the gastric cancer group than in the normal group,but E-cadherin was weaker(p<0.05).there was a negative correlation between the expression of p CNA and E-cadherin in gastric carcinoma(r=-0.741,p=0.000).p CNA expression differed significantly between gastric cancer patients with and without lymph node metastasis and between patients at different t stages.E-cadherin expression also differed significantly between gastric cancer patients with and without lymph node metastasis(p<0.05).High t stage and positive p CNA expression were risk factors for the prognosis of patients with gastric cancer(RR>1),while the positive expression of E-cadherin was a protective factor(RR<1).the sensitivity,specificity,and accuracy of p CNA positivity in predicting the 3-year survival of patients with gastric cancer were 93.33%,38.89%,and0.64,respectively;while these values for E-cadherin negativity were 80.0%,41.67%,and 0.59,respectively.When p CNA positivity and E-cadherin negativity were combined,the sensitivity,specificity,and accuracy were66.67%,66.67%,and 0.67,respectively.CONCLUSION Combined detection of p CNA and E-cadherin can improve the accuracy of assessing the prognosis of patients with gastric cancer.

Clinical Significance of p53, Proliferating Cell Nuclear Antige and bcl-2 Expression in Bladder Transitional Cell Carcinoma

Objective: To correlate the frequency of p53 mutations, bcl-2 expression and the proliferation status (proliferating cell nuclear antigen, PCNA) in patients with bladder cancer with cell proliferation, apoptosis and their clinico-pathologic ?ndings. Methods: Para?n-embedded sections from 39 super?cial (T1G1-G3) and 23 invasive (T2-T4a G3 N0M0) primary transitional cell carcinomas (TCC) in the bladder were investigated immunohistochemically for p53, bcl-2 and PCNA. The median follow-up was 37 months; 24 had recurrences. The proliferation index (PI) was expressed as a percentage of the PCNA-positive cells in the tumor cells. Apoptosis was detected by terminal deoxy-nucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL), and the apoptotic index (AI) was expressed as a percentage of the TUNEL- positive tumor cells. Results: P53 mutation was identi?ed in 50 patients (80.6%). The mutation was most common in tumors of grade 3 (91.3%) as compared to grade 2 (78.5%) and grade 1 (72.7%, P<0.05). Stage pT2 tumors had a higher frequency of p53 mutation (95.7%) as compared to pTa-1 tumors (74.3%, P<0.01). Only 14 tumors (22.5%) expressed bcl-2; grade 3 tumors expressed bcl-2 signi?cantly more frequently (P<0.05); there was no correlation between bcl-2 and tumor stage. There was no interrelation between p53 mutation and bcl-2 expression (P>0.05). The PI ranged from 17.2% to 41.8% (median 22.4%) and the AI from 1.9% to 3.5% (median 2.9%) in bladder cancer. Statistical analyses revealed a close associations between PI, AI and tumor grade and stage of bladder cancer. Conclusion: P53 mutation correlates with invasion. P53 and PCNA overexpression may o?er valuable additional prognostic information in bladder tumors. With the progression of the tumor grade, cell proliferation may be accompanied by frequent apoptosis in bladder cancer, but the PI increased much more than the AI.

Clinical significance of telomerase activity in peritoneal lavage fluid from patients with gastric cancer and its relationship with cellular proliferation

AIM： To evaluate the efficacy of telomerase activity assay and peritoneal lavage cytology （PLC） examination in peritoneal lavage fluid for the prediction of peritoneal metastasis in gastric cancer patients, and to explore the relationship between telomerase activity and proliferating cell nuclear antigen expression.METHODS： Telomeric repeated amplification protocol （TRAP）-enzyme-linked immunosorbent assay （ELISA） was performed to measure the telomerase activity in 60 patients with gastric cancer and 50 with peptic ulcer. PLC analysis of the 60 patients with gastric cancer was used for comparison. The proliferating cell nuclear antigen （PCNA） in gastric carcinoma was immunohistochemically examined.RESULTS： The telomerase activity and PLC positive rate in peritoneal lavage fluid from patients with gastric cancer was 41.7% （25/60）, and 25.0% （15/60）, respectively. The positive rate of telomerase activity was significantly higher than that Qf PLC in the group of pT, （15/16 vs 9/16, P 〈 0.05）, P1-3 （13/13 vs 9/13, P 〈 0.05） and diffuse type （22/42 vs 13/42, P 〈 0.05）. The patients with positive telomerase activity, peritoneal metastasis, and serosal invasion had significantly higher levels of average PCNA proliferation index （PI）, （55.00 ± 6.59 vs 27.43 ± 7.72, 57.26 ±10.18 vs 29.15 ±8.31, and 49.82 ± 6.74 vs 24.65 ±7.33, respectively, P 〈 0.05）.CONCLUSION： The TRAP assay for telomerase activity is a useful adjunct for cytologic method in the diagnosis of peritoneal micrometastasis and well related to higher proliferating activity of gastric cancer. The results of this study also suggest a promising future therapeutic strategy for treating peritoneal dissemination based on telomerase inhibition.

Evaluation of germ-cell kinetics in infertile patients with proliferating cell nuclear antigen proliferating index

Aim: To explore the usefulness of proliferating cell nuclear antigen proliferating index (PCNA PI) in the pathologicaldiagnosis and treatment of male infertility. Methods: Testicular biopsy specimen obtained from 48 cases of male in-fertility and 2 normal controls were fixed and embedded. The sections were stained with anti-PCNA monoclonal anti-bodies or haematoxylin/eosin. Proliferating index (PI), expressed as the percentage of germ-cell nuclei positivelystained with PCNA antibody, was assessed from more than 20 seminiferous tubules or 600 germ-cells. Results: Theinfertile patients were divided into 4 groups: Group 1, normal spermatogenesis (14 cases); Group 2, hypospermato-genesis (16 cases); Group 3, germinal arrest (10 cases); Group 4, Sertoli cell only syndrome (8 cases). The PCNAPI of normal control testis was 86.5 % (mean value). Group 3 had a significantly lower PCNA PI (29.8 %) than nor-mal testis; Group 1 and 2 had similar Pis (82.3% and 82.3%, respectively) as the control testis. PI of the negativecontrol (Group 4) was 0 as no germ-cells were found. Conclusion: PCNA PI is useful for assessing germ-cell ki-netics, especially for pathological diagnosis of germinal arrest which is difficult to differentiate by routine HE stainingtechnique. In germinal arrest, there is a significantly lowered PCNA PI, which is an indication of DNA synthesis dete-rioration, suggesting the use of therapies be different from those for hypospermatogenesis. (Asian J Androl 2001 Mar;3: 63-66)

Mast cell density and the context of clinicopathological parameters and expression of p185,estrogen receptor,and proliferating cell nuclear antigen in gastric carcinoma

AIM:To investigate the relationship between the mast cell density(MCD)and the context of clinicopathological parameters and expression of p185,estrogen receptor(ER), and proliferating cell nuclear antigen(PCNA)in gastric carcinoma. METHODS:Mast cell,p185,ER,and PCNA were detected using immunohistochemical S-P labeling method.Mast cell was counted in tissue of gastric carcinoma and regional lymph nodes respectively,and involved lymph nodes(ILN)were examined as usual. RESULTS:MCD was significantly related to both age and depth of penetration(x^2=4.688,P<0.05 for age and x^2=9.350, P<0.01 for depth of penetration)between MCD>21/0.03 mm^2 and MCD≤21/0.03 mm^2 in 100 patients;MCD in 1-6 ILN group patients was significantly higher than that in 7-15 ILN or>15 ILN group patients(u=6.881,8.055,P<0.01); There were significant differences intergroup in positive expression rate of p185,ER and PCNA between MCD>21/ 0.03 mm^2 and MCD≤21/0.03 mm^2 in 100 patients. CONCLUSION:Mast cell may have effect on inhibiting invasive growth of tumor,especially in the aged patients; The number of mast cells,in certain degree,may predicate the number of involved lymph nodes,which is valuable for assessment of prognosis;MCD was related to the expression of p185,ER,and PCNA in gastric carcinoma.It suggests that mast cell accumulation may inhibit the proliferation and the dissemination of the gastric carcinoma. INTRODUCTION Recently,many studies have reported on the association of mast cell with various tumorst.In several malignancies,mast cell has been found to correlate with growth,penetration and prognosis of tumor.Therefore,our study was undertaken to investigate the relationship between the mast cell density (MCD)and the context of clinicopathological parameters and expression of p 185,estrogen receptor(ER),and proliferating cell nuclear antigen(PCNA)in gastric carcinoma.

The Relationship between Apoptosis and the Expression of Proliferating Cell Nuclear Antigen and the Clinical Stages in Gastric Carcinoma

The relationship between the apoptosis and the expression of proliferating cell nuclear antigen (PCNA) and the clinical stages in gastric cancers was studied. By using terminal deoxynucleotidyl transferase mediated nick end labelling (TUNEL) technique and PCNA immunohistochemical staining, the apoptosis and the expression of PCNA in tissue of gastric carcinoma were assayed in situ, the index of apoptosis (AI), index of PCNA (PI) and the rate of AI/PI were calculated. AI and PI in gastric cancer tissues were (6.5±3.7) % and (49.8±15.9) % respectively, and the rate of AI/PI was 0.13±0.05, which were obviously different from those of normal gastric mucosa in paragastric cancer ( P <0.01). With the advanced TNM stages of gastric carcinoma, the AI was decreased, PI was increased and the rate of AI/PI decreased in gastric carcinoma. There was significant difference in them between the gastric cancer tissues and normal gastric mucosa in pericarcinoma in TNM stage Ⅱ to Ⅳ ( P <0.05). It was suggested that the decreased apoptotic cells and the increased proliferating cells were obviously related to the tumor genesis and tumor progression in gastric carcinoma. The AI, PI and the rate of AI/PI would become the prognostic factors in advanced gastric carcinoma.

RELATIONSHIP BETWEEN PROLIFERATING CELL NUCLEARANTIGEN EXPRESSION AND ITS MALIGNANCY POTENTIAL IN COLORECTAL CARCINOMA

Objective: To study the relationship between proliferating cell nuclear antigen expression and its malignancy potential in colorectal carcinoma. Methods: Paraffin sections of 86 patients with advanced colorectal carcinoma were assessed by immunohistochemical study, using a mouse monoclonal antibody (pc-10, DAKO Co. USA) to check proliferating cell nuclear antigen (PCNA). To compare PCNA with conventional clinicopathologic factor, including p53 overexpression, tissue carcinoembnyonic antigen immunoreactivity pattern and flow cytometric DNA ploidy for assessing tumor malignancy potential. In addition, recurrence and survival of patients with advanced colorectal carcinoma after curative resection were analyzed in accordance with degree of PCNA expression. Results: PCNA-labeling index (PCNA-LI) increased significantly as the tumor stage advanced (p=0.0001). Strong correlations were observed between PCNA-LI and various pathologic parameters, including histologic differentiation (P=0.0027), lymphatic invasion (P=0.0001), vascular invasion (P=0.0001), lymph node metastasis (P=0.0001), and liver metastasis (P=0.0036). Mean PCNA-LI was also significantly higher in tumor with DNA aneuploidy (P=0.0006) and negative (P=0.01). Linear relationships were demonstrated between PCNA-LI and clinical outcomes; Recurrence rate was significantly greater in the group with higher than the mean PCNA-LI, who underwent curative resection (P<0.01), and three-year survival rates for curative cases with higher than the mean PCNA-LI were significantly poorer than those with lower than mean PCNA-LI (P<0.005). Conclusion: There were correlations between PCNA-LI and various pathologic parameters, PCNA-LI increased significantly as the tumor stage advanced in colorectal carcinoma, the rates of recurrence and death got higher as PCNA-LI increased after curative resection for colorectal carcinoma.

Effect of preoperative transcatheter arterial chemoembolization on proliferation of hepatocellular carcinoma cells

AIM： To evaluate the effect of preoperative transcatheter arterial chemoembolization （TACE） on proliferation of hepatocellular carcinoma （HCC） cells. METHODS： A total of 136 patients with HCC underwent liver resection. Of 136 patients, 79 patients received 1 to 5 courses of TACE prior to liver resection （TACE group）, who were further subdivided into four groups： Group A （n = 11） who received i to 4 courses of chemotherapy alone; Group B （n = 33） who received i to 5 courses of chemotherapy combined with iodized oil; Group C （n = 23） who received i to 3 courses of chemotherapy combined with iodized oil and gelatin sponge; and Group D （n = 12） who received 1 to 3 courses of chemotherapy combined with iodized oil, ethanol and gelatin sponge. The other 57 patients only received liver resection （non- TACE group）. The expressions of Ki-67 and proliferating cell nuclear antigen （PCNA） protein were detected in the liver cancer tissues by immunohistochemical method. RESULTS： The Ki-67 protein expression was significantly lower in Groups C and D as compared with non-TACE group （31.35% ± 10.85% vs 44.43% ± 20.70%, 30.93% ± 18.10% vs 44.43% ± 20.70%, respectively, P 〈 0.05）. The PCNA protein expression was significantly lower in Groups C and D as compared with non-TACE group （49.61% ± 15.11% vs 62.92% ± 17.21%, 41.16% ± 11.83% vs 62.92% ± 17.21%, respectively, P 〈 0.05）. The Ki-67 protein expression was significantly higher in Group A as compared with non-TACE group （55.44% ± 13.72% vs 44.43% ± 20.70%, P 〈 0.05）. The PCNA protein expression was significantly higher in Groups A and B as compared with non-TACE group （72.22% ± 8.71% vs 62.92% ± 17.21%, 69.91% ± 13.38% vs 62.92% ± 17.21%, respectively, P 〈0.05）. CONCLUSION： Preoperative multi-material TACE suppresses the proliferation of HCC cells, while a single material embolization and chemotherapy alone enhance the proliferation of HCC cells.

Cloning and characterization of proliferating cell nuclear antigen gene of Alexandrium catenella (Dinoflagellate) with respect to cell growth

Harmful algal blooms （HABs） have been affecting negatively the shellfish and aquaculture industries around the world. Though a lot of efforts have been made to disclose the changes of environmental factors involved and their effects on the HABs events, the molecular mechanism of this process remains unclear. To address this problem, proliferating cell nuclear antigen gene （pcna） was isolated and characterized from Alexandrium catenella. It showed high homology to those of other dinoflagellates （89% and 91% homology to Pfiesteria piscicid and Pyrocystis lunula, respectively）, and also 42%–43% homology to those of plant and animals. The expression level of pcna revealed by quantitative real time PCR was the lowest at the late lagging cell growth phase, increased to the highest at the late exponential phase, and then decreased at the stationary phase. Though the cell growth rate was also changing, no positive correlation between pcna expression level and cell growth rate was displayed throughout the whole cell growth stages （r 2 =0.024 6）. However, the pcna expression level had the similar trend with the change of cell growth rate throughout the whole growing process, e.g., from increasing at the earlier cell growth stage to decreasing at the following stages, though slightly lagging to the latter.

Inhibition of PCNA Antisense Oligonucleotides Mediated by Liposome on mRNA Expression and Proliferation of h-RPE Cells

Summary： The proliferating cell nuclear antigen （PCNA） gene expression was blocked and retinal pigment epithelium （RPE） proliferation was inhibited by using antisense oligonucleotides （AS-ODN） mediated by liposome, to find a new genetic therapy of proliferative vitreoretinopathy （PVR）. RPE cells cultured in vitro were transfected with synthetic fluorescence labled AS-ODN mediated by liposome-Lipofectamine, and the intracellular distribution and persistence time of AS-ODN were dynamically observed. AS-ODN （0.07, 0.28 and 1.12 μ mol/L and sense oligonucleotides （S-ODN with the same concentrations as AS-ODN） mediated by liposome were delivered to the RPE cells cultured in vitro, and CPM values were measured by ^3H-TdR incorporation assay and analyzed statistically by variance by comparison with blank control group. Expression ofPCNA mRNA in RPE cells was detected by in situ hybridization after the treatment of different concentrations of PCNA AS-ODN and S-ODN, and the average optic density （AOD） was measured by image analysis system and was subjected to q-test and correlation analysis with CPM. Our results showed that AS-ODN mediated by liposome could quickly aggregate in cellular plasma and nuclei in 30 min and 6 h, and stayed for as long as 6 days. AS-ODN （0.28 and 1.12 μmol/L） markedly suppressed proliferation of RPE cells in a dose-dependent manner with the difference being statistically significant （P〈0.05 and P〈0.01, repectively） as compared with blank control group. AOD was well correlated with CPM （r=0.975）. It is concluded that liposome could increase transfection efficiency of AS-ODN in RPE cells, and AS-ODN could sequence-specifically suppress PCNA mRNA expression and proliferation of human RPE cells.

Spontaneous Proliferation in Organotypic Cultures of Mouse Cochleae

Cells in mammalian cochleae virtually stop proliferation and exit cellular circle before birth. Consequently, hair cells and spiral ganglion neurons destroyed by ototoxic factors cannot be replaced through proliferative regeneration. However, substantial proliferation occurs in organotypic cultures of cochleae from postnatal mice. In the present study, we studied the time course of proliferative growth in cultures of mouse cochlea explants obtained from up to 12 postnatal days. The mitotic nature of this growth was confirmed by bromodeoxyuridine (BrdU) staining and expression of proliferation cell nuclear antigen (PCNA) evaluated with real-time quantitative poly-merase chain reaction(RT-PCR). Similar growth time course was found in the cochlear explants of different postnatal ages. The new growth reached its maximum at around 2 days in culture followed by a slow-down, and virtually stopped after 5 days of culture. The possible mechanisms and the significance of this proliferation are discussed.

EXPRESSION OF P53 PROTEIN AND PROLIFERATING CELL NUCLEAR ANTIGEN IN HUMAN GESTATION TROPHOBLASTIC DISEASE

To study the relationship between p53 protein, proliferating cell nuclear antigen (PCNA) expression and benign or malignant gestational trophoblastic disease (MGTD). Methods: The histotomic sections of 48 patients with gestational trophoblastic disease and 24 patients of normal chorionic villi were stained using immunohistochemistry. The monoclonal antibodies were used to determine p53 protein and PCNA. Results: The frequency of p53 and PCNA positive expression were significantly different among the chorionic villi of normal pregnancy, hydratidiform mole (HM) and MGTD. But neither p53 nor PCNA has any relation with the clinical staging or metastasis of MGTD. Conclusion: Both P53 and PCNA are valuable in diagnosis of human gestational trophoblastic disease.

Proliferating cell nuclear antigen clamp associated factor,a potential proto-oncogene with increased expression in malignant gastrointestinal tumors

Gastrointestinal(GI)cancers,including malignancies in the gastrointestinal tract and accessory organs of digestion,represent the leading cause of death worldwide due to the poor prognosis of most GI cancers.An investigation into the potential molecular targets of prediction,diagnosis,prognosis,and therapy in GI cancers is urgently required.Proliferating cell nuclear antigen(PCNA)clamp associated factor(PCLAF),which plays an essential role in cell proliferation,apoptosis,and cell cycle regulation by binding to PCNA,is a potential molecular target of GI cancers as it contributes to a series of malignant properties,including tumorigenesis,epithelial-mesenchymal transition,migration,and invasion.Furthermore,PCLAF is an underlying plasma prediction target in colorectal cancer and liver cancer.In addition to GI cancers,PCLAF is also involved in other types of cancers and autoimmune diseases.Several pivotal pathways,including the Rb/E2F pathway,NF-κB pathway,and p53-p21 cascade,are implicated in PCLAF-mediated diseases.PCLAF also contributes to some diseases through dysregulation of the p53 pathway,WNT signal pathway,MEK/ERK pathway,and PI3K/AKT/mTOR signal cascade.This review mainly describes in detail the role of PCLAF in physiological status and GI cancers.The signaling pathways involved in PCLAF are also summarized.Suppression of the interaction of PCLAF/PCNA or the expression of PCLAF might be potential biological therapeutic strategies for GI cancers.

Expression of Survivin, p53 and its relationship with apoptosis, proliferation in hepatocellular carcinoma(HCC)

Objective：To investigate the expression of Survivin p53 and its relationship with apoptosis, proliferation in hepatocellular carcinoma （HCC）. Methods：The expression of Survivin, p53 and the proliferation of tumor cells marked by proliferation cell nuclear antigen （PCNA） in 42 cases of HCC were assessed by immunohistochemical method. TUNEL was used to detect apoptosis. Results：Survivin protein was expressed in 30 of 42 cases of HCC（71.4%） and in 4 of 34 cases of adjacent cirrhosis tissues（11.8%）. Expression of Survivin protein was negative in 10 cases of normal tissues. Survivin protein positive expression rate in HCC was significantly higher than adjacent cirrhosis tissues and normal tissues（P 〈 0.001）. The increased Survivin protein expression in cancer was significantly associated with histological grade（P = 0.003）, p53 protein（P = 0.013）, survival time（P 〈 0.05） and the ratio of proliferative index to apoptotic index（P〈 0.01）, but was not significantly correlated with age, sex, clinical stage, tumor size, metastasis, AFP, HBs-Ag（P 〉 0.05）. Conclusion：There is a marked increased expression of Survivin in HCC, which may play an important role in breaking the balance of proliferation and apoptosis of HCC cells. The correlation between Survivin and p53 expression in HCC indicates that cooperation between Survivin and p53 plays a certain role in occurrence and/or development of HCC.

Effects of caffeic acid phenethyl ester on proliferation of vascular smooth muscle cells in rats

Objective： To investigate the inhibitory effect of caffeic acid phenethyl ester（CAPE） on the proliferation of vascular smooth muscle cells （VSMC） activated by lipopolysaccharide （LPS） and to clarify its mechanism. Methods： VSMC activated by LPS （1 mg-L^-1） were treated with CAPE at different concentrations. The inhibitory effecfs of CAPE on the proliferation of VSMC were determined by methabenzthiazuron（MTT） colorimetry. The effects of CAPE on the expression of proliferating cell nuclear antigen （PCNA） and Survivin protein in VSMC were evaluated by immunocytochemistry staining technique （SABC method）. Cell cycle was analyzed by flow cytometry（FCM） with propidiumiodide （PI） labeling method. The relative expression level of Survivin mRNA was measured with real-time quantified RT-PCR technique. Results. CAPE exerted significant inhibitory effects on. proliferation of VSMC at concentrations ranging from 5 mg·L^-1 to 80 mg·L^-1, decreased the rate of cells positive for PCNA and Survivin protein and repressed the expressioh of Survivin mRNA in a dose- and time-dependent manner （P 〈 0.05）. FCM analysis displayed that CAPE up-regulated the ratio of G0/G1 stages and reduced the percentage of VSMC in S stage （P 〈 0.05）. Conclusion： CAPE can significantly inhibit the proliferation of VSMC activated by LPS in a dose- and time-dependent manner, which may be carded out through regulating cell cycle and repressing the expression of PCNA and Survivin.

PROLIFERATING CELL NUCLEAR ANTIGEN(PCNA) IN OVARIAN CARCINOMA AND ITS RELATION TO LYMPH NODE METASTASIS AND PROGNOSIS

Objective: To investigate expression of proliferating cell nuclear antigen (PCNA) in ovarian epithelial cancer and its relation to lymph node metastasis, outcome of second look laparotomy (SLL) and prognosis Methods: Monoclonal antibody PC10 was used to stain PCNA in archival paraffin embedded tissues Results: PC10 immunostaining was performed successfully in all 74 primary and 31 intraperitoneal metastatic tumors The expression levels of PCNA were significantly increased in 31 metastatic tumors compared with their primary tumor from the same patients (7 94 vs 6 89, P=0 042) The expression levels was more elevated in bilateral than in unilateral ovarian cancer, but it was not associated with lymph node metastasis, clinical stage, histological grade and subtype In 28 patients with stage III ovarian cancer undergone SLL, the mean immunoreactive score (IRS) of PCNA of the primary tumor was significantly higher in patients with negative SLL than in those with positive SLL (7 59 vs 6 10, P =0 03) Since chemotherapy was performed following surgical debulking, negative SLL more frequently seen in patients with high PCNA expression might suggest better chemotherapeutic sensitivity due to higher proliferation fraction of tumor cell Univariate analysis of survival indicated that the overall survival was inversely associated with the level of PCNA expression, while multivariate analysis with Cox's model showed that independent prognostic factors were the residual tumor after primary debulking ( P<0 001 ) and clinical stage ( P <0 05), followed by PCNA expression( P =0 09) Conclusion: The expression of PCNA may beuseful in predicting the patients' prognosis, but is not correlated with lymph node metastasis